I have a dozen er1 robots that were purchased by our high school back in 2005. I teach teachnology and the first year they all worked great. Over the first summer though, 8 of them just failed. It's the RCM module and I can't understand how they failied by just sitting in their boxed over the summer. They were stored up on shelves so there was not a water issue. Anyone have any clue. Or, does anyone know how to fix them or who can repair them. I called the company many times but got no explanations. It was a great part of my curriculum and I hope to bring the robots back. I am sure it is the RCM because I have swapped components between robots to prove it.

I bet there is oxide on the RCM's PCB and at power on something shortened. You need to take apart the RCM, clean the oxide and let the board dry, then try to power up and measure the voltage after the regulator. If you get 5V there, and the RCM is still non responsive, it may be hard to fix because some ICs may be fried. I hope it's just a fuse and no hard damage done.

If they are not recoverable, you may need to replace them completly. Evolution Robotics sells a new RCM, that may be an option.

Good luck!

I am not really happy with the RCM I have so I want to replace it with a home made controller. For this I am working on a smaller size prototype that can be scaled up by just replacing the motor driver. Also, I want to use DC motors instead of steppers. But if you need to, I can draw up a schematic and board that can use the same motors ER1 uses. The only difference will be the ER1 software will not be able to recognize it as a regular RCM, but it could be used in Python with the same commands as the original. I do not have the firmware working yet, but that could be a project you can do better than me.